Electrochemical performance of sodium compound NaNi0.4Fe0.2Mn0.4O2 as symmetrical electrode for low temperature ceramic fuel cells

The electrochemical performance and related mechanisms of NaNi 0.4 Fe 0.2 Mn 0.4 O 2 (NNFM) as symmetrical electrode for low-temperature ceramic fuel cells were investigated. After reduction in H2 at elevated temperature, sodium compounds including NaOH molten salt are formed in the NNFM anode, which diffuses into the GDC electrolyte, creating a composite electrolyte of "GDC-sodium compounds" with high ionic conductivity. The ionic conductivity of the "GDC-sodium compounds" composite electrolyte generated in the cell with GDC/NNFM (weight ratio 8/2) composite as the electrolyte layer reached 0.116 S center dot cm-1 at 550 degrees C. The maximum power density of the cell with the "GDC-sodium compounds" composite electrolyte reaches 273 mW center dot cm- 2 at 550 degrees C. The presence of molten salt in the sodium compounds enhances the electrolyte's ionic conductivity while also contributing to the filling of internal pores and ensuring effective fuel gas sealing. The formation of sodium compounds molten salt within the cell also significantly reduces the polarization resistance associated with the electrode reactions in the electrodes on both sides of the cell.